Electrolyte for lithium secondary battery and lithium secondary battery comprising same

Abstract

According to exemplary embodiments, an electrolyte for a lithium secondary battery which includes an additive including a compound represented by a specific formula; an organic solvent; and a lithium salt may be provided. Thereby, the lithium secondary battery including the electrolyte for a lithium secondary battery may provide excellent high-temperature characteristics and other performances (e.g., initial resistance, rapid charge performance, room-temperature capacity characteristics, etc.).

1 . An electrolyte for a lithium secondary battery comprising:
 an additive which comprises a compound represented by Formula 1 below;   an organic solvent; and   a lithium salt:   
       
         
           
           
               
               
           
         
         (in Formula 1, R 1  and R 2  are each independently a substituted or unsubstituted C 2 -C 8  cyclic ether group, and L 1  and L 2  are each independently a substituted or unsubstituted C 1 -C 5  alkylene group). 
       
     
     
         2 . The electrolyte for a lithium secondary battery according to  claim 1 , wherein R 1  and R 2  are each independently an unsubstituted C 2 -C 5  cyclic ether group, and L 1  and L 2  are each independently an unsubstituted C 1 -C 3  alkylene group. 
     
     
         3 . The electrolyte for a lithium secondary battery according to  claim 1 , wherein R 1  and R 2  are each independently an unsubstituted C 4  cyclic ether group, and L 1  and L 2  are each independently an unsubstituted C 1  alkylene group. 
     
     
         4 . The electrolyte for a lithium secondary battery according to  claim 1 , wherein the additive is included in an amount of 0.1 to 5% by weight based on a total weight of the electrolyte. 
     
     
         5 . The electrolyte for a lithium secondary battery according to  claim 1 , wherein the additive is included in an amount of 0.2 to 2% by weight based on a total weight of the electrolyte. 
     
     
         6 . The electrolyte for a lithium secondary battery according to  claim 1 , wherein the organic solvent includes a linear carbonate solvent and a cyclic carbonate solvent. 
     
     
         7 . The electrolyte for a lithium secondary battery according to  claim 1 , further comprising at least one auxiliary additive selected from the group consisting of a cyclic carbonate compound, a fluorine-substituted carbonate compound, a sultone compound, a cyclic sulfate compound and a phosphate compound. 
     
     
         8 . The electrolyte for a lithium secondary battery according to  claim 7 , wherein the auxiliary additive is included in an amount of 0.05 to 10% by weight based on a total weight of the electrolyte. 
     
     
         9 . The electrolyte for a lithium secondary battery according to  claim 7 , wherein the auxiliary additive is included in an amount of 0.1 to 5% by weight based on the total weight of the electrolyte. 
     
     
         10 . The electrolyte for a lithium secondary battery according to  claim 7 , wherein a ratio of a weight of the auxiliary additive to a weight of the additive in the electrolyte is 0.1 to 10. 
     
     
         11 . A lithium secondary battery comprising an electrode assembly in which a plurality of cathodes and a plurality of anodes are repeatedly stacked;
 a case in which the electrode assembly is housed; and   the electrolyte for a lithium secondary battery according to  claim 1  housed in the case together with the electrode assembly.